1. Field of the Invention
The present invention relates to a recording tape cartridge accommodating, within a case, a reel on which is wound a recording tape, such as a magnetic tape or the like, which is used as a recording/playback medium mainly for computers or the like.
2. Description of the Related Art
Conventionally, magnetic tape cartridges have been known in which a magnetic tape, which is used as a data recording/playback medium of a computer or the like, is wound on a single reel, and the reel is accommodated in a case A leader member, such as a leader pin, a leader tape, or a leader block, is provided at the distal end of the magnetic tape. A pull-out mechanism provided at a drive device pulls the leader member out from an opening of the magnetic tape cartridge, and winds the magnetic tape, which is fixed to the leader member, onto a take-up reel of the drive device.
A reel gear is formed in an annular form in the center of the bottom surface of a reel which emerges from an open hole formed in the bottom surface of the magnetic tape cartridge. Due to a driving gear, which is provided at a rotating shaft of the drive device, meshing with this reel gear, the reel is driven to rotate. By rotating the reel of the magnetic tape cartridge and the take-up reel of the drive device synchronously, data can be recorded onto the magnetic tape, and data recorded on the magnetic tape can be played back.
As shown in FIG. 4, reel area ribs 104, 106, which are arc-shaped, stand erect intermittently at an upper case 100 and a lower case 102. A reel 108, on which a magnetic tape (not shown) is wound, is rotatably accommodated at the inner sides of the reel area ribs 104, 106.
A clearance of about 0.5 mm is provided between, on the one hand, the reel area ribs 104, 106, and, on the other hand, an upper flange 114 and a lower flange 116 forming the reel 108, so as to compensate for dimensional errors caused by offset of the center or an error in inclination or the like of a magnetic tape cartridge 112 with respect to a drive device, when a driving gear (not shown) of the drive device meshes with a reel gear 110 provided at the reel 108. Movement of the reel 108 is restricted by the upper flange 114 or the lower flange 116 abutting the reel area rib 104 or the reel area rib 106, respectively.
However, when the magnetic tape cartridge 112 is dropped or the like, due to the impact at the time of the drop, the outer edge portion of the upper flange 114 or the lower flange 116 of the reel 108 hits the corner portion of the reel area rib 104 or the reel area rib 106 which stands upright intermittently. There is therefore the concern that the upper flange 114 or the lower flange 116 may deform, break, or the like.